Go on, admit it: The sheets you have on your bed right now are the same ones that were there this time last week... and maybe even the week before that. It's a habit most of us have fallen into at least sometimes (myself included), and one that seems harmless enough. Emphasis on seems. In fact, a lot of gross things happen when you don't change your sheets regularly, and once you learn the truth, you might be prompted to change your unhygienic ways.
The consumer site Mattress Advisor surveyed 1,000 Americans about their bedding-cleanliness beliefs and habits. Their responses were surprising (and not suitable for reading at mealtime). It seems that on average, we change our sheets only once every 24 days, and our pillowcases a day or two after that. (Isn't it just easier to get the whole bed taken care of at the same time?) Men leave their sheets on 10 days longer than women do, and single men don't swap out the bedding until nearly 45 days. While we can try to justify our habits if our sheets don't "look dirty," it's harder to understand why women wait nearly five days to wash their sheets after having sex, and men wait almost 12 days. (Yep, that's nearly two weeks of sleeping on sheets with dried... um... fluids.)
What happens to those thin cloths that stand between our bodies and the mattress might surprise you. What health risks they pose might make you queasy. Either way, you'll probably want to strip your bed and head for the washing machine right after you read this. (I did.)
1. Your bed becomes a bacteria rave.
Every time you lie down at night, you transfer all the germs that accumulated on your body during the day onto your sheets and pillowcases. And the longer you go between washings, the more bacteria in your bed build up. Just how much? The Amerisleep mattress company decided to find out. They recruited volunteers to swab their unwashed bedding throughout a four-week period, and had scientists analyze the samples. The results? After just one week, the used sheets had accumulated 5 million colony-forming units (CFU) of bacteria. That's more than 24,000 times the amount found on the average bathroom doorknob. After four weeks, that number jumps to over 11 million CFUs, which makes it 39 times more germy than a pet food bowl and 5 times more than a toothbrush holder.
The most commonly isolated bacteria on the soiled sheets was gram-negative rods, which can cause pneumonia and antibiotic-resistant infections. The researchers also found bacilli, the bacteria responsible for some types of food poisoning. Makes you want to think twice about eating in bed, doesn't it?
2. Your acne could flare up.
Next time you're tempted to flop into bed with your foundation and mascara still on, use every bit of willpower you can to stumble into the bathroom and clean your face. It's for your own good. As DC dermatologist Dr. Elizabeth Tanzi told Redbook, those particles of makeup collect in your pillowcase, accumulating bacteria which go right back on your face. The result: whiteheads, blackheads, and worsening of the zits you already have. Even if you don't wear makeup, you still deposit skin oil on your bedding which can linger and cause infections. So don't go to bed without scrubbing up — and change your pillowcases frequently.
3. You share your bed with tiny critters.
If you're easily grossed out, brace yourself: You're not alone when you sleep. Microscopic insects called dust mites love to hang out in sheets, mattresses, and other cloth or upholstered surfaces where dust gathers. These places are a rich source of the skin flakes you shed every day, which dust mites happen to feed on. These creatures are also a major trigger of allergies and asthma, especially in areas that experience humid summers, explained The New York Times. (To add to the gross factor, it's the mites' poop that we're actually allergic to.) Frequent washing and changing sheets can help keep the bugs at bay. You can also buy mattress covers designed to block mites from getting into your bed (like these, from The Allergy Store), which can help keep your allergies under control.
4. You might contract athlete's foot.
Hygiene doctor Lisa Ackerley told the Daily Mail that the bacteria and fungus that collect in bedsheets over a period of time can potentially enter our bodies through open cuts, sores and other breaks in the skin. Among them is the fungus that causes athlete's foot, which can be spread through contact with surfaces where the affected foot has been. So if your partner has the infection, they risk spreading it to you through the bed you share, especially if you haven't put fresh sheets on in a while.
Disgusted yet? Wait, it gets better: Other yucks that can be transmitted through dirty sheets include ringworm, jock itch, toenail fungus, and external yeast infections in various skin crevices.
5. Worst-case scenario: You could end up in the hospital.
Okay, this one is a pretty long shot, but it's still possible. As Vice pointed out, one of the bacteria that collect in dirty bedsheets is staphylococcus aureus, also known as staph. The staph bacteria lives in the warm, moist areas of our body, and most of the time, it does no harm. If it enters the bloodstream through a cut, however, that's a different story. Staph-based infections can range from urinary tract infections to skin boils, styes on the eye, cellulitis, and even MRSA, the antibiotic-resistant infection that can be fatal in certain cases, according to KidsHealth.
Bottom line: Leaving your sheets on for days on end can do more harm than you think. Experts recommend changing your sheets every seven to 10 days, or more often if you've been sick, sleep in the nude, sweat a lot, don't shower before bed, or have a pet that sleeps with you. Launder your bedding on the hottest washer setting, followed by a tumble in the dryer, to kill mites and bacteria. Then you really can rest easy, knowing you're both comfortable and clean.